Process for the production of elements made of hydrated cellulose



United States Patent 3,114,592 PROCESS FOR THE PRODUCTION OF ELEMENTS MADE OF HYDRATED CELLULOSE Eduard Barthel], Hermann-Dietrich Schmidt-Neuhaus,

and Friedrich Hilgers, all of Krefeld, Germany, assignors to Chemische Fabrik Stockhausen & Cie, Krefeld, Germany, a corporation No Drawing. Filed July 11, 1961,, Ser. No. 123,116 Claims priority, application Germany July 15, 1960 6 Claims. (Cl. 18-54) This invention is concerned with a process for the production of elements made of hydrated cellulose.

It is known to manufacture fibres and films from hydrated cellulose by forcing viscose through nozzles or slots into baths which advantageously contain acid salts, the aforesaid elements being formed by decomposition of the cellulose xanthate contained in the viscose. The process may be modified in a number of ways. These modifications serve mainly to facilitate the carrying out of the process and/ or the improving of the quality of the elements produced in accordance with the process. One modification which is frequently employed consists in using substances which facilitate the production of the viscose, for example, at the time of xanthation, by shortening the time required for xanthate formation by emulsifying the carbon disulphide and/ or dispersing impurities in extremely fine form in the viscose, so that, for example, satisfactory filtration is guaranteed. An improvement in the filament-drawing capacity is apparent with these additives. Furthermore, the disadvantageous deposition of impurities from the viscose and/or from the spinning bath at the spinnerets is avoided. On account of the products added to the spinning baths or products reaching the baths from the viscose, the said baths remain free from clouding substances which otherwise usually sediment. This effect is only shown to its best effect in the spinning bath if the additive has been added directly to spinning bath. Ethoxylated amines and pyridinium compounds have inter alia been used as such additives as well as sulphonated and sulphated oils.

Rayons which in use show particularly good properties are obtained by spinning viscoses which contain cellulose with a relatively high average degree of polymerisation. However, such viscoses have a higher viscosity. In order to be able to spin such viscoses, they must be brought to a higher temperature so that the viscosity becomes lower.

With the prior known viscose additives which are active at boundary surfaces and which contain basic nitrogen, however, the disadvantage arises that at temperatures above 40 C. they no longer remain clearly soluble in the viscose or in the spinning bath. With this undesirable change in their solubility they lose their efficacy during the spinning operation.

It has been found that amine oxides of the general Formula I below do not show these disadvantages and can best be used as additives to the viscose and also to the spinning bath.

According to the invention therefore, there is provided a process for the production of elements of hydrated cellulose from viscose in which there is added to the viscose or to a bath in which the viscose is to be precipitated one or more amine oxides of the general formula cording to the invention are, for example dimethyl lauryl, diethyloctyl, tributyl, dimethyl butyl, triisopropyl, triiso- 3,114,592 Patented Dec. 17, 1963 octyl, methoxyethylmethyl lauryl, dimethyl stearyl, diethyl oleyl, dimethyl cyclohexyl, dicyclohexyl methyl and dimethyl phenyl amine oxides.

The addition of the compounds according to the invention to the viscose results in substantially all the improvements indicated above, these compounds when added to the viscose being substantially as effective in the precipitation bath as if they had been directly added thereto.

In order that the invention may be well understood, the following examples are given, by way of illustration only:

Example 0.2 g. of dimethyl laurylamine oxide are added per litre to a viscose normally used for the production of textile filaments. The eflfect of the additive is that the viscose becomes completely transparent, can easily be filtered and shows excellent filament-drawing capacity. Its surface tension is also reduced by at least 50% and, on spinning into a conventional Miiller bath, it does not cause any incrustation of the spinnerets. Impurities in the precipitation bath are also avoided.

Example 2 If an unripe viscose is processed, as in Example 1, using 0.8 g./l. of diethyloctylamine oxide, the effects mentioned in Example 1 are also produced. In addition, the milkiness which always occurs when processing unripe viscose is avoided.

Example 3 0.5 g./l. of dimethyl laurylamine oxide are added to a normal viscose to which a matting agent or a spinning dye-stuff has been added. The amine oxide can also be added by first of all being mixed with the pigment, the mixture then being incorporated in the viscose. If this viscose is spun in the usual manner, more intensive matting or dyeing effects are produced than those obtained when amine oxide is not used. It is obvious that the amine oxide produces an improved dispersion of the pigment in the viscose, whereby a better utilisation of the pigment is obtained.

Example 4 If 2 g./l. of tributylamine oxide are added to a viscose normally used for the production of cord filaments, the stretchability is improved to a surprising degree and thereby a cord rayon with a high strength value is produced.

We claim:

1. In a process for the production of elements of hydrated cellulose by precipitation of viscose in a precipitation bath the step of adding to the viscose at least 0.2 g./l. referred to the viscose of an amine oxide of the general formula wherein R R and R are selected from the group consisting of aliphatic hydrocarbon radicals, cycloaliphatic hydrocarbon radicals, and phenyl, the sum of the C atoms of the R substituents being from 6 to 24.

2. In the process of claim 1, the step of adding said amine oxide to the precipitation bath instead of to the viscose.

3. In the process for the production of elements of hydrated cellulose by precipitation of viscose in a precipitation bath the step of adding to the viscose 0.2 g./l.

referred to the viscose of an amine oxide selected from the group consisting of Dimethyl laurylamine oxide,

Diethyl octylamine oxide, Tributylamine oxide,

Dimethyl butylamine oxide, Triisopropylamine oxide, Methoxyethyl methyl laurylamine oxide, Dimethyl stearylamine oxide,

Diethyl oleylamine oxide,

Dimethyl cyclohexylamine oxide, Dicyclohexyl methylamine oxide, and Dimethyl phenylamine oxide.

4. In the process of claim 3, the step of adding said amine oxide to the precipitation bath instead of to the viscose.

5.A process for the production of elements of hydrated cellulose from viscose which comprises the step of adding to the viscose 0.2 g./l. referred to the viscose of an amine oxide of the general formula R1 R2 N=O Ra wherein R R and R are selected from the group con- 4 sisting of alkyl, cycloalkyl, alkoxyalkyl, and phenyl, the sum of the C atoms of the R substituents being from 6 to 24, precipitating the viscose by introduction thereof into a precipitating bath and recovering the precipitated hydrated cellulose.

6. A process for the production of spun hydrated cellulose which comprises the steps of adding to viscose 0.2 g./l. referred to the viscose of an amine oxide of the formula Ra wherein R R R are selected from the group consisting of alkyl, cycloalkyl, alkoxyalkyl, and phenyl, the sum of the C atoms of the R substituents being from 6 to 24, introducing the viscose through spinnerets into a spinning bath and recovering the spun hydrated cellulose therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 2,179,195 Polak et al. Nov. 7, 1939 2,422,021 Kline et a1. June 10, 1947 2,519,227 Collins Aug. 15, 1950 

1. IN A PROCESS FOR THE PRODUCTION OF ELEMENTS OF HYDRATED CELLULOSE BY PRECIPITATION OF VISCOSE IN A PRECIPITATION BATH THE STEP OF ADDING TO THE VISCOSE AT LEAST 0.2 G./1. REFERRED TO THE VISCOSE OF AN AMINE OXIDE OF THE GENERAL FORMULA 